To start off, lets take a look at a spec shall we?
NOTE: THIS POST WAS MADE IN PATCH 4.0.3a pre cata look for a newer post if this is outdated.
Basically its your average arcane spec.
This spec is NOT for leveling. It provides optimal damage and survivability required for raiding.
Once youve got your spec going your gonna want some gem help.
As arcane mages the meta well use is a Chaotic skyflare diamond.
This meta is a +21% crit strike and a +3% damage bonus meta.
Once again OPTIMAL for damage.
As for your red sockets, just stick to Brilliant cardinal ruby for +20 intellect.
Now, blue sockets are important because they will activate the meta!
The optimal blue gem to use is Purified Dreadstone for +10 intellect & spirit.
Ah probably the most confusing of them all, go for the Reckless ametrine for +10 intellect and +10 haste.
Now enchanting is VERY important. Choose wisely.
Instead of listing all the enchants you could use (there are many) and it depends on your gold situation because there are lower quality versions of MANY of them.
Head on over HERE
That will help you find the right enchant your looking for.
(Wowpopular is an EXCELLENT site, look around its really easy to use)
ROTATION....(Not much of a rotation anyway..)
This is probably the most IMPORTANT part of the whole thing. Yeah you could have the best enchants, gemming and spec.... but you need to know what buttons to press!
Here is a simple way of doing it!